[CCPC]

Hi everyone,
 
I'm looking for a little insight into, what most here would consider, a somewhat simple chemistry question. I own a pressure cleaning business, of which I use a number of different chemicals to achieve optimal results in my work. The main one, being that of liquid chlorine (sodium hypochlorite). I'm looking for the best choice of chemical to effectivly nuetralize the chlorine, but of course in a rather safe manor for myself, and for the surface I am applying it to.
I clean roofs using liquid chlorine (10.5% sodium hypochlorite) dilluted with water to about a 5% to 7% solution (basicly, I usually cut it to about half strength). I apply this solution to the roof, let it dwell until it has effectively killed the algea, and then rinse. The problem is, even while using great care in prewetting the landscaping, and thourghly rinsing afterwards, I'm still running into problem with burning some of the landscape.
In light of this, I've been trying to find the right chemical to effectively nuetralize the chlorine before rinsing it off the roof. My first thought was to use an acid such as oxalic, but was informed that sodium hypochlorite comes from hypochlorous acid, and for that reason, would not be an effective chemical for nuetrilzing. After doing a little research, I've found that sodium thiosulfate is used quite frequently for nuetrilzing chlorine, but, from what I've found, this is usually for well dilluted amounts such as in tap water, so I'm a little uncertain of how well this would work in nuetrilzing a very strong solution, such as what I apply to the roof. Also, it seems from what I've read on the msds for sodium thiosulfate, that its not the most stable chemical, and can present somewhat of a fire hazard when exposed to a moderate amount of heat, as well as other chemicals.

If you would be so kind, I would love to here some feedback on this dilima of mine, and hopfully find the safest chemical and method for this.  :confused1:

[saibot]

Use AMMONIA!    .  Actually, I'm just kidding.  Please don't, whatever you do.  Very dangerous.


Sodium thiosulfate will work.  This would neutralize whatever sodium hypochlorite that is left over.

But then we have another problem.  We are left with tetrathionate-containing compounds, which as far as I know, is also bad.

It is irritating to eyes, skin, and your respitory system.  But I'm thinking that it will be in such small quantities, it wont be a problem.  But then again, we don't wan't any pollution of the environment.  Maybe someone else can elaborate more on this....

[CCPC]

Use AMMONIA!    .  Actually, I'm just kidding.  Please don't, whatever you do.  Very dangerous.

LOL!! Don't worry about that, I'm not that green.

But then we have another problem.  We are left with tetrathionate-containing compounds, which as far as I know, is also bad.

Tetrathionate-containg compounds? Not sure what this. I'll have to do a little research on this.

It is irritating to eyes, skin, and your respitory system.  But I'm thinking that it will be in such small quantities, it wont be a problem.  But then again, we don't wan't any pollution of the environment.  Maybe someone else can elaborate more on this....

Are you speaking of the effects of the sodium thiosulfate, or the tetrathionate-containing compounds? If these are the extent of the physical effects, it shouldn't be a problem, as I always ware the proper PPE including repirator w/face shield, gloves, and such.

I very much appreciate the help so far. Anyone else?

[saibot]

Tetrathionate-containg compounds? Not sure what this. I'll have to do a little research on this.

The tetrathionate ion is S₄O₆^2-.  This would be one of the end products of that reaction.

Are you speaking of the effects of the sodium thiosulfate, or the tetrathionate-containing compounds? If these are the extent of the physical effects, it shouldn't be a problem, as I always ware the proper PPE including repirator w/face shield, gloves, and such.

I was speaking of the effects of tetrathionate.

Hope that clears some things up.